1. Field of the Invention
The present invention relates generally to telecommunications systems and methods for providing localized service area services, and specifically to providing efficient reservation and allocation of radio resources within a localized service area.
2. Background and Objects of the Present Invention
Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world. A standardization group, European Telecommunications Standards Institute (ETSI), was established in 1982 to formulate the specifications for the Global System for Mobile Communication (GSM) digital mobile cellular radio system.
With reference now to FIG. 1 of the drawings, there is illustrated a GSM Public Land Mobile Network (PLMN), such as wireless network 10, which in turn is composed of a plurality of areas 12, each with a Mobile Services Switching Center (MSC) 14 and an integrated Visitor Location Register (VLR) 16 therein. The MSC/VLR areas 12, in turn, include a plurality of Location Areas (LA) 18, which are defined as that part of a given MSC/VLR area 12 in which a mobile station (MS) 20 may move freely without having to send update location information to the MSC/VLR area 12 that controls the LA 18. Each Location Area 18 is divided into a number of cells 22. Mobile Station (MS) 20 is the physical equipment, e.g., a car phone or other portable phone, used by mobile subscribers to communicate with the wireless network 10, each other, and users outside the subscribed network, both wireline and wireless.
The MSC 14 is in communication with at least one Base Station Controller (BSC) 23, which, in turn, is in contact with at least one Base Transceiver Station (BTS) 24. The BTS 24 is the physical equipment, illustrated for simplicity as a radio tower, that provides radio coverage to the geographical part of the cell 22 for which it is responsible. It should be understood that the BSC 23 may be connected to several BTSs 24, and may be implemented as a stand-alone node or integrated with the MSC 14. In either event, the BSC 23 and BTS 24 components, as a whole, are generally referred to as a Base Station System (BSS) 25.
With further reference to FIG. 1, the PLMN Service Area or wireless network 10 includes a Home Location Register (HLR) 26, which is a database maintaining all subscriber information, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information. The HLR 26 may be co-located with a given MSC 14, integrated with the MSC 14, or, alternatively, can service multiple MSCs 14, the latter of which is illustrated in FIG. 1.
The VLR 16 is a database containing information about all of the MSs 20 currently located within the MSC/VLR area 12. If an MS 20 roams into a new MSC/VLR area 12, the VLR 16 connected to that MSC 14 will request data about that MS 20 from its home HLR database 26 (simultaneously informing the HLR 26 about the current location of the MS 20). Accordingly, if the user of the MS 20 then wants to make a call, the local VLR 16 will have the requisite identification information without having to reinterrogate the home HLR 26. In the aforedescribed manner, the VLR and HLR databases 16 and 26, respectively, contain various subscriber information associated with a given MS 20.
Within the GSM standards, there are features and capabilities defined which allow groups of subscribers to be managed according to a number of operator specific criteria, e.g., CAMEL or USSD. Future trends in GSM system platform development are geared towards customized system solutions to enhance radio access solutions to take into account, for example, indoor environments, such as micro and pico cells 22 within an office building.
One such customized solution is the Localized Service Area (LSA), which offers subscribers or groups of subscribers different service features, costs and access rights within a regionally restricted area or areas. The LSA concept is especially beneficial for businesses by allowing a company to provide cellular service to its employees while located within the building or buildings constituting the company.
As shown in FIG. 2 of the drawings, an LSA 250 can consist of a cell 22a or a number of cells 22a within one or more GSM PLMN's 10. LSA cells 22a can be implemented on top of existing GSM PLMN cells 22b, with coverage overlapping between LSA cells 22a and GSM cells 22b. In addition, the cells 22a constituting the LSA 250 may not necessarily provide continuous coverage.
In any cellular environment, an available radio resource guarantees the completion of a call. However, for cells 22a belonging to the LSA 250, a number of channels are typically reserved for LSA mobile subscribers, e.g., employees, in order to ensure that the LSA mobile subscribers can gain access to the LSA network 250. An Exclusive Access (EA) function provides exclusive access to radio resources only to mobile subscribers registered with the LSA 250. Thus, if an employee invites a business associate who is not registered with the LSA 250 into the office building, the business associate would not be able to access the LSA radio resources. The business associate would then only be able to make a wireless call if an overlapping GSM cell 22b provides coverage to the office building. However, with the EA function, the radio resources of the LSA 250 may not be efficiently utilized by the LSA mobile subscribers at all times. These situations are undesirable for many LSA 250 network operators.
Therefore, a Preferential Access (PA) function within the LSA 250 can be implemented to provide preference for radio resources to mobile subscribers that subscribe to the LSA 250, which ensures the availability of radio resources for the LSA mobile subscribers when needed. However, even in an LSA 250 having the PA function, these reserved channels may not be efficiently used by the LSA mobile subscribers.
For example, an inefficiency can arise if the LSA 250 has reserved twenty percent of the available radio resources for registered LSA mobile subscribers, and only five percent of the reserved radio resources are being used by registered LSA mobile subscribers. If the entire eighty percent of unreserved radio resources are being used by non-registered mobile subscribers (hereinafter referred to as public mobile subscribers), if one more public mobile subscriber attempts to access the LSA network 250, the public mobile subscriber will not be allowed access, even though fifteen percent of the radio resources are still available.
As another example, an inefficiency can arise in the opposite situation, in which the entire twenty percent of available radio resources that have been reserved for registered LSA mobile subscribers are being utilized by the LSA mobile subscribers. If a registered LSA mobile subscriber then attempts to access the LSA network 250, the registered LSA mobile subscriber may not be allowed access to the LSA network 250 because the LSA mobile subscriber will be competing with other public mobile subscribers to gain access to the LSA network 250. This is also undesirable for the LSA 250 network operator and the registered LSA mobile subscriber, because LSA's 250 are typically created to provide specific cellular services and features for the registered LSA mobile subscribers.
It is, therefore, an object of the present invention to provide an adaptive reservation of radio resources within an LSA in order to achieve efficient channel allocation and utilization of radio resources.